Apparatuses and methods for sound recording, manipulation, distribution and pressure wave creation through energy transfer between photons and media particles

ABSTRACT

Recording, manipulating, distributing and creating sound pressure waves in one or more media by employing an apparatus that transfers the energy between photons and particles of the media is disclosed. An exemplary apparatus comprises one or more lasers and an isotropic or anisotropic medium for photon processing and distribution. An exemplary method comprises determining the target locations for sound pressure wave recording, manipulating or creation; transmitting photons to the target locations; transferring photon energy to media particles to create or manipulate a sound pressure wave; or transferring energy of media particles to photons for recording or manipulating a sound pressure wave.

RELATED APPLICATIONS

This Application claims priority from U.S. Provisional PatentApplication No. 62/295,347, filed Feb. 15, 2016 and incorporated hereinby reference in its entirety.

TECHNICAL FIELD

The present disclosure describes various apparatuses and methodsrelating to sound recording, creation, manipulation and distribution,involving the transfer of energy between photons and media particles.

BACKGROUND

Alexander Graham Bell and Sumner Tainter first demonstrated conversionof sound to light and light to sound in the 1880s with the invention ofthe photophone. The acoustic vibrations of a speaker's voice on aflexible mirror caused variations in the scattering of light by themirror and the scattered light was converted into sound by a hard rubberdiaphragm upon which the scattered light was incident; the sound wasthen amplified using a tube. Bell's observation that certain solidmaterials produced sound upon absorption of light (the rubber diaphragmin this case) later came to be known as the “photoacoustic effect”.

The photoacoustic effect is the generation of sound waves in a materialdue to absorption of electromagnetic radiation. The primary cause is thevarying expansion and contraction of material due to thermal effects,which results in the generation of a pressure wave. Spectroscopy,imaging and calorimetry are some of the widest applications of thiseffect. Attempts have been made to use the photoacoustic effect forother sound applications such as a speaker, e.g. U.S. Pat. No.4,641,377.

The photoacoustic effect can only generate sound and does not result inthe recording of sound, which limits its application. For medical andindustrial ultrasonic applications and audio applications the drawbacksof this method are the expensive and cumbersome construction, the needfor temperature and pressure control of the material, typically gas, andinadequate sound intensity so that sound generated for practical useoutside the material must be coupled with the other medium andamplified.

Present day optical microphones are constructed so as to convert soundpressure waves into modulation of light properties such as phase,polarization or intensity. Typically, diaphragm displacement is detectedwith lasers and interferometry is used to determine changes in lightproperties after interaction with sound waves.

Other recent developments for sound recording attempt to overcome thelimitations of conventional microphones that convert sound waves intovibrations of a diaphragm or plate. The diaphragm or plate that respondsto sound pressure waves has a finite mass and size and takes a finiteamount of time (delay) to respond to changes in sound wave pressure. Theuse of a diaphragm in conventional microphones results in non-lineardistortion, limited frequency response, and limited dynamic range.

These recent innovations rely on the direct interaction of light withsound and use the effects of refractive index modification of air bysound pressure waves to measure modified light propagation which isdetermined by heterodyning the detected signal of a reference and signallaser beam. See, e.g. U.S. Pat. No. 6,014,239 and U.S. Pat. No.6,147,787. In “Proposal of Optical Wave Microphone and PhysicalMechanism of Sound Detection” by Yoshito Sonoda and Toshiyuki Nakamiya,incident laser light onto a sound wave gets weakly diffracted and isdetected by an optical detector.

Drawbacks of the aforementioned approaches include expensiveconstruction and calibration, complex optoelectronics to convert opticalinto electric signals and eliminate noise, and the dependence ofmicrophone sensitivity on light path and hence device size.

Audio signals are conventionally carried in AM and FM radio wavesthrough space and as electrical signals through wires. Some headphonesand headsets are physically connected to the sound-generating devicesuch as a computing device and constrain the location of the listenerwith respect to the device. Current wireless technologies for soundtransmission include Bluetooth, Wi-Fi and other wireless technologies.The power required to transmit, receive and process the signals issignificant, however, particularly for longer transmission ranges. Rangeis particularly limited for low energy transmission technologies.

Methods of transmitting optical signals over long distances use opticalfiber to avoid electrical interference. See, e.g., U.S. Pat. No.5,262,884, U.S. Pat. No. 6,055,080 and U.S. Pat. No. 6,483,619. Opticalfibers have been used to eliminate common noise, radio frequencyinterference, electromagnetic interference and mains hum and to increasetransmission distances. In most sound applications the microphone needsto be located away from the sound amplifiers and speakers. This requiresthe unamplified electrical microphone signals to be sent over longdistances using cables. To support higher bit rates and wider bandwidth,point-to-point interfaces such as Ethernet, High Definition MultimediaInterface (HDMI) and optical fiber have been increasingly used to carrymultiple signals along with other data. Jitter performance of Ethernetand HDMI affects sound quality. The length of the electrical cables islimited by electrical signal losses in the cable, capacitances and strayelectromagnetic pick-up in the cable.

However, transmission over optical fiber entails a physical connectionand requires conversion to electrical signals at the sound creation orstorage location. The electro-optic conversion requires costlyprocessing of the electrical signal at or near the place where the soundis captured. The optical signals after conversion to electrical signalsneed to be connected to a preamplifier before the signal can beamplified with a power amplifier. Moreover, for any wired distributionarrangement, the planning and layout of cables are critical and canbecome costly over large distances.

Other forms of electromagnetic radiation, including visible light, canalso carry audio signals. “Simultaneous acquisition of massive number ofaudio channels through optical means”, by Gabriel Pablo Nava, YutakaKamamoto, Takashi G. Sato, Yoshifumi Shiraki, Noboru Harada, andTakehiro Moriya, NTT Communication Science Laboratories, NipponTelegraph and Telephone Corporation describes an optical system based onVisible Light Communication. The method for simultaneous recording ofmultiple audio channels and distributing the data employs LEDs and animager to receive the data. Although theoretically thousands of channelscan be recorded and transmitted, the paper explains the limitationsimposed by hardware requirements for a high frame rate imager andsufficient image processing capability. This limits the scalability ofthe system. Other Visible Light Communication systems to transmit audioare described in, e.g., U.S. Pat. No. 8,131,154, U.S. Pat. No.7,949,259, CN 102723987, US 20090203286, WO 2013051808.

The present disclosure sets forth below one or more implementations ofsound distribution methods and/or apparatuses that avoid the problems ofnoise, poor jitter performance, and interference in distribution andthat allow operation at much lower power than existing technologies forthe same transmission distance.

Exemplary implementations in accordance with the present disclosureavoid the use of complex audio processing electronics and the associateddrawbacks of known devices discussed above.

Laser-based photophoresis employs the radiation pressure force of laserlight to impart momentum to media particles. Historically it has beenused to manipulate particles, biological cells, atoms, and molecules inmedicine, science and research. Photophoresis has applications inbeam-powered propulsion in space, development of optical traps, and inthe field of “atom optics” for manipulating media particles. “History ofOptical Trapping and Manipulation of Small-Neutral Particle, Atoms, andMolecules”, by A. Ashkin provides an introduction to the subject and abrief history.

As described below, embodiments of the present disclosure exploitlaser-based photophoresis in a variety of applications in which sound isrecorded, created and/or manipulated. A variety of such applicationswill now be discussed. Improved methods and apparatuses for transmittingsound are also described below.

SUMMARY

Exemplary implementations in accordance with the present disclosurerelate to methods and apparatuses for recording, manipulating,transmitting and creating sound pressure waves using laser light for thetransfer of sound pressure wave energy to photons (sound recording andmanipulating), distribution of photons to target locations, and transferof photon energy to media particles to create sound pressure waves(sound creation and manipulating). Manipulation of a sound pressure waverefers to modifying the properties of the wave such as amplitude,frequency, and phase. The sound pressure waves may be classified as anyof the following: audible sound, infrasound and ultrasound.

Exemplary implementations in accordance with the present disclosurerelate to methods and apparatuses for defining and creating zones,defined by one or more surfaces or bounded volumes, by directing photonsin 3-dimensional (3-D) space to target locations that define the zones.By defining and creating these zones, the sound properties within themcan be controlled.

Exemplary implementations in accordance with the present disclosurerelate to methods and apparatuses for the detection and identificationof objects for the purpose of determining target locations fordistributing, recording, manipulating and creating sound pressure waves.

In one aspect, the present disclosure relates to microphones. In anotheraspect, it relates to loudspeakers, headsets, personal sound amplifiersand hearing aids. In another aspect, it relates to a method ofgenerating pure 3-D sound. In another aspect, it relates to soundmeasurement systems. In another aspect, it relates to the transmissionof sound in one or more media. In another aspect, it relates to themixing and mastering of sound. In another aspect, it relates to soundproduction apparatuses such as musical instruments. In another aspect,it relates to noise reduction and cancelation. In another aspect, itrelates to soundproofing. In yet another aspect, it relates to recordingsound within defined regions in space. In yet another aspect, it relatesto sound wave generation within defined regions in space. In yet anotheraspect, it relates to manipulating, eliminating and filtering sound atdefined regions in space. In yet another aspect of the presentdisclosure, it relates to ultrasonic pressure wave creation,distribution and receipt of reflected and transmitted ultrasoundpressure waves for applications including but not limited to medical andindustrial applications.

Exemplary implementations in accordance with the present disclosuresolve multiple problems in sound recording and reproduction byeliminating mechanical diaphragms and electronics employed during soundrecording, manipulating and sound wave creation.

Exemplary implementations in accordance with the present disclosuresolve multiple problems in transmitting sound by eliminatingelectromagnetic wave transmission and associated electronics and wiresthat would otherwise be required for sound distribution.

Exemplary implementations in accordance with the present disclosureenjoy the advantages of perfectly flat or near perfectly flat frequencyresponse with little or no distortion, low noise, large dynamic rangethat is orders of magnitude greater than human hearing (resolution),frequency independent directionality, sound image location independencefrom speaker location and arrangement, very low latency, and low powerconsumption. It additionally reduces the physical footprint of presentday sound devices that use current sound-based technologies, therebyenhancing the portability of such devices and the ease of use. Asignificant advantage is that mechanical and electrical designcomplexity are significantly reduced without sacrificing performance.

Exemplary implementations in accordance with the present disclosureprovide greater flexibility and functionality in a single apparatus andcan work in multiple physical media such as but not limited to air,water, living tissue, plastic and glass.

Exemplary implementations in accordance with the present disclosure makesound recording, distribution, manipulation, and pressure wave creationpossible by exchanging energy between photons and media particles,thereby overcoming the above-mentioned problems with existing mechanicaland electronic devices used in sound related applications.

In exemplary implementations in accordance with the present disclosure,some or all processing is performed in the optical (vs. electrical)domain, including: detecting the apparatus selection inputs; determiningtarget sound recording, manipulation and creation locations; determiningand applying required modifications to photon properties in order tomodify sound properties; reading sound data encoded as properties ofphotons or optically encoded in an isotropic or anisotropic medium;detecting, classifying, recognizing and identifying objects; anddetermining how to interact with similar devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1. is a simplified block diagram of an exemplary embodiment of anapparatus in accordance with the present disclosure.

FIG. 2 is a simplified block diagram of an illustrative arrangement of aplurality of apparatuses used together to record, distribute, manipulateand generate sound pressure waves.

FIG. 3 illustrates the radiative exchange of energy between photons anda mirror for explaining photophoretic effects in implementations of thepresent disclosure.

FIG. 4A illustrates the exchange of energy between photons and mediaparticles setting up vibrations in the media and resulting in soundgeneration.

FIG. 4B illustrates directing photons within the ear canal for energyexchange between photons and media particles inside the ear canal.

FIG. 5 is a simplified block diagram of an exemplary embodiment of anapparatus including components for using ultrasound, electromagneticwaves or laser generated photons to determine target locations for soundpressure wave recording, creation or for manipulating sound properties.

FIG. 6 illustrates a sequence for detecting target locations,distributing photons to these target locations and generating,manipulating and/or recording sound.

FIG. 7 is an illustration of a defined volume used as a sound creationzone.

FIG. 8 is an illustration of a defined volume used as a sound recordingzone.

FIG. 9 is a sequence for defining and controlling sound propertiesacross volume boundaries.

FIG. 10 is a simplified illustration of an exemplary apparatus thatincludes, in addition to optical transduction and distributioncomponents, components for receiving, performing optical to digitalconversion and processing reflected ultrasonic pressure waves anddisplaying data.

FIG. 11 is a simplified block diagram of an exemplary embodiment of anapparatus in accordance with the present disclosure for a speaker typeapplication.

FIGS. 12A-12C show a flowchart illustrating various implementations inaccordance with the present disclosure.

DETAILED DESCRIPTION

The following merely illustrates the principles of the disclosure. Itwill thus be appreciated that those skilled in the art will be able todevise various arrangements which, although not explicitly described orshown herein, embody the principles of the disclosure and are includedwithin its spirit and scope. More particularly, while numerous specificdetails are set forth, it is understood that embodiments of thedisclosure may be practiced without these specific details and in otherinstances, well-known circuits, structures and techniques have not beshown in order not to obscure the understanding of this disclosure.

Furthermore, all examples and conditional language recited herein areprincipally intended expressly to be only for pedagogical purposes toaid the reader in understanding the principles of the disclosure and theconcepts contributed by the inventor(s) to furthering the art, and areto be construed as being without limitation to such specifically recitedexamples and conditions.

Moreover, all statements herein reciting principles, aspects, andembodiments of the disclosure, as well as specific examples thereof, areintended to encompass both structural and functional equivalentsthereof. Additionally, it is intended that such equivalents include bothcurrently-known equivalents as well as equivalents developed in thefuture, i.e., any elements developed that perform the same function,regardless of structure.

Thus, for example, it will be appreciated by those skilled in the artthat the diagrams herein represent conceptual views of illustrativestructures embodying the principles of the invention.

In addition, it will be appreciated by those skilled in art that anyflow charts, flow diagrams, and the like represent various processeswhich may be substantially represented in computer readable medium andso executed by a computer or processor, whether or not such computer orprocessor is explicitly shown.

The functions of the various elements shown in the Figures, includingany functional blocks labeled as “processors” or “processing”, may beprovided through the use of dedicated hardware as well as hardwarecapable of executing software in association with appropriate software.When provided by a processor, the functions may be provided by a singlededicated processor, by a single shared processor, or by a plurality ofindividual processors, some of which may be shared. Moreover, explicituse of the term “processor” or “controller” should not be construed torefer exclusively to hardware capable of executing software, and mayimplicitly include, without limitation, digital signal processor (DSP)hardware, network processor, application specific integrated circuit(ASIC), field programmable gate array (FPGA), read-only memory (ROM) forstoring software, random access memory (RAM), and non-volatile storage.Other hardware, conventional and/or custom, may also be included.

Software modules, or simply modules which are implied to be software,may be represented herein as any combination of flowchart elements orother elements indicating performance of process steps and/or textualdescription. Such modules may be executed by hardware that is expresslyor implicitly shown.

FIG. 1 shows a block diagram of an exemplary optical apparatus 100 whichmay be contained in an optional enclosure 150. Optical apparatus 100includes controls 110, a crystal 130, and two or more coherent lightsources, such as lasers. Two lasers 120 and 140 are shown in FIG. 1.Lasers 120 and 140 are positioned to direct laser light toward crystal130 so that the laser light beams emitted therefrom are mutuallyorthogonal with respect to their directions of propagation; i.e. thelasers 120 and 140 are positioned so that the axis of one beam is at aright angle to the axis of the other beam. This orthogonality can beexploited to obtain a specific phase and polarization relationshipbetween photons in the beams. When two beams of laser light cross insidea type of nonlinear crystal, they mutually influence each other'spropagation. In some cases, one beam will donate its photons to theother beam resulting in the nonreciprocal transfer of energy between thebeams. The control of light by light is the optical analog of thecontrol of electrons by electrons in transistors. The photorefractiveeffect is an effective optical nonlinearity in which the coherentinterference of the two beams produces a pattern of bright and darkfringes. These fringes cause electrical charge to separate inside thephotorefractive crystal, producing space-charge field patterns thatmimic the light patterns. The electric fields, in turn, through thelinear electro-optic effect, modify the refractive index of thematerial, creating a diffraction grating. This light-induced diffractiongrating diffracts light from the two laser beams, redirecting thephotons of one beam in the direction of the other beam. When the phaserelationship is just right between the transmitted and diffracted beams,then net constructive interference will occur in one transmitted beam,but destructive interference will occur in the other beam. Thephotorefractive effect is the basis for dynamic holography. Hologramsthat move and change in time in response to changing light images arecalled dynamic holograms. They are recorded in real-time just as anordinary hologram is, using two laser beams. One laser beam carries theinformation from the object, while the other laser beam acts as areference. The use of two light beams rather than one (as in ordinaryphotography) makes it possible for a hologram to record phase as well asintensity. Dynamic holograms are constantly changing, or updating, asthe information on the signal beam changes. As such, dynamic hologramsproduced in a crystal can perform an information processing function. Indynamic holography it is possible to simultaneously read and write ahologram in a photorefractive material.

Laser light photons from lasers 120 and 140 interact with crystal 130resulting in the transfer of information from the crystal 130 to thephotons or from the photons to the crystal. Space-charge field patternsinside crystal 130 serve as the means of storing information. While acrystal is shown in FIG. 1, crystal 130 may be replaced by otherisotropic or anisotropic media in other embodiments. Crystal 130 can beimplemented with photorefractive materials such as inorganic materialsthat include one or more of gallium arsenide (GaAs), barium titanate(BaTiO3), lithium niobate (LiNbO₃), bismuth silicon oxide (Bi₁₂SiO₂₀),potassium niobate (KNbO₃), and strontium niobate (SrNb₂O₆), and organicmaterials that include one or more of a polymer, polymer composites, andamorphous composites. Other anisotropic materials that can be used alsoinclude liquid crystals, photonic crystals and various dielectrics.Semiconductors, like GaAs, can act as dynamic holographic media. Theyhave high carrier mobilities that make the refresh rate of the hologramsfast enough for audio and video applications. While birefringence isusually obtained using an anisotropic crystal, it can also result froman optically isotropic material in various ways such as deformation,suspension in another material,the Kerr effect, and temperaturereduction to name a few. Some examples of isotropic materials includesome polymers, glass, photonic crystals and isotropic liquid crystals.

Other embodiments may include other quantum memory storage techniquesemploying materials such as laser-cooled gases and trapped atoms,impurity-doped crystals, semiconductor materials, and optomechanicalsystems.

In an exemplary diment, one or both of lasers 120 and 140 can beimplemented with laser diodes.

In operation, apparatus 100 transmits photons emerging from crystal 130to one or more target locations. Sound pressure waves from an externalsource arriving at the target locations cause media particles at theselocations to vibrate. The energy of the vibrations is transferred fromthe media particles to the photons at the target locations. Fromreturning photons, apparatus 100 determines the change in photonproperties resulting from the energy transfer and stores theseproperties in crystal 130 or in another medium (not shown) as opticallyencoded data relating to the sound pressure waves arriving at the targetlocations. The nonlinear paths of the returned photons in the crystal isindicative of the history of photon interactions.

In addition or alternatively to thus capturing or recording soundpressure waves at one or more target locations as described above,apparatus 100 can be used to create sound pressure waves at one or moretarget locations. In this case, apparatus 100 transmits photons thatconvey sound data in the form of photon properties to one or more soundpressure wave creation target locations. Energy of the photonstransmitted to said target locations is transferred to media particlesat the target locations to create sound pressure waves at the targetlocations in accordance with the sound data. Controls 110 can be used todefine the sound properties of the resultant sound pressure waves thatwill be created by apparatus 100 at the target locations.

The aforementioned target locations, whether for sound capture or soundcreation, can be defined using selection inputs of controls 110, byoptically encoded data in crystal 130, or by automated discovery oftarget locations by the apparatus. Controls 110 may include mechanicalcontrols (such as knobs, buttons, and sliders), electronic controls(such as a touchscreen), software controls, or optical controls (such asvisible light, optical gestural interfaces, or holographic interfaces)or a combination of these controls. Controls 110 may be internal and/orexternal to apparatus 100. An exemplary implementation includes one ormore mechanical switches, each of which controls the activation of arespective light source, such as an LED, thereby generating an opticalsignal based on a mechanical action. When photons of the optical signalarrive at crystal 130, the interaction of the electric field with theelectric fields in the crystal can be used to determine the state of thecontrol e.g. on or off. A sound property such as volume can be encodedin a bank of N LEDs (with 2^(N) combinations assuming that only on andoff state of the LED is used as states for control). Another exemplarycontrol mechanism may include a remote control that interfaces opticallywith apparatus 100.

Alternatively, instead of using controls 110, the definition of soundproperties and/or target locations can be transmitted to apparatus 100from one or more other apparatuses.

In an exemplary arrangement shown in FIG. 2, apparatus 210, which can beimplemented using apparatus 100 of FIG. 1, receives optically encodedsound data, encoded as photon properties, from another similar apparatus200. Apparatus 210 optically transmits the optically encoded sound datato apparatus 220 and prior to transmission may modify the properties ofthe optically encoded sound data. Apparatus 210 can be envisioned to bea repeater, amplifier, attenuator, mixing or mastering device, or anyother device that can change the properties of sound. Apparatus 220, inturn, creates sound pressure waves by transferring the energy of photonsto the media particles.

Any arrangement such as that of FIG. 2 can be implemented to allowapparatuses to communicate with each other and distribute the soundpressure wave recording, manipulating, distributing and creating tasks.

As mentioned, methods and apparatuses of the present disclosure exploitthe exchange of energy between media particles and photons. The directedexchange of momentum between microscopic particles and photons has beendescribed in “Photophoresis of micrometer-sized particles in thefree-molecular regime”, by Shahram Tehranian, Frank Giovane, JurgenBlum, Yu-Lin Xu, Bo A. S. Gustafson [ix]. The photophoretic force andvelocity on microscopic particles has been calculated in thefree-molecular flow regime and for constant illumination. The phenomenonof directed momentum exchange is exploited in various implementationsdescribed herein for audio and other applications and in bothdirections: i.e., from photons to media particles and from mediaparticles to photons.

The momentum exchange occurring between photons and media particles,also referred to as “energy exchange” or “energy transfer,” will now bedescribed in greater detail with reference to FIG. 3.

Photons have both wave and particle characteristics and observe waveparticle duality. Though they have no mass, photons carry momentum, asdescribed by the De Broglie equation, p=h/λ.

When photons are reflected, such as from mirrors, or interact withmatter, an exchange of momentum takes place. At all stages, totalmomentum is conserved as in classical mechanics, even if the actualdefinition of momentum changes slightly and is not now equal tomass*velocity. Suppose then that a photon is bounced between two mirrors310 and 320 arranged a distance d apart as shown in FIG. 3. The photon,traveling with speed c, the speed of light, travels distance d in timet=d/c. After leaving mirror 310, the photon travels to mirror 320,undergoes reflection at mirror 320, and then travels back to mirror 310.The time taken to return to mirror 310 is thus t=2d/c and the photonstrikes each mirror c/(2d) times per second. Each time the photonstrikes a mirror it transfers momentum equal to h/λ−(−h/λ)=2h/λ to themirror so the force exerted on the mirror is equal to the rate of changeof momentum, c/(2d)×2h/λ=ch/(dλ). The force exerted is very small. Onephoton with a wavelength of 10−10 m bouncing between mirrors 1 m apartexerts a force of 2*10−15 N.

The pressure exerted by photons is the principle behind the solar sailusing the radiative pressure of photons. Photons from the Sun bounce offa large flat sail in space, pushing the sail away from the Sun. Forsound related applications, when enough photons are directed towards aparticle such as a molecule, the collective force can be used to vibratethe molecule. The oscillatory nature of the photophoretic force in afree molecular flow is obtained for certain values of the normalizedsize parameter and refractive index of the molecule. The vibrations inmolecules can be adjusted by varying the direction and magnitude of thephotophoretic force of photons at the impact area. A vibrating moleculeproduces similar vibrations in neighboring molecules, which do the sameto their neighbors, and so forth, spreading the oscillations outward andleading to the creation of a sound pressure wave. FIG. 4A shows thisphenomenon, in which photons 410 interact with media particles 420. Ifthe photons are transferring energy to media particles, then each mediaparticle in the path of energy transfer is displaced from its positionand vibrates in a direction parallel to the direction of energytransport, thereby resulting in a pressure wave that is the soundpressure wave traveling in the medium.

FIG. 4B depicts photons distributed to an illustrative target location,in this case a person's ear canal. Once photons arrive at the ear canal,the photophoretic effect is produced inside the ear canal resulting inthe generation of sound pressure waves.

In reverse to the phenomenon of imparting energy from photons to mediaparticles, when a vibrating molecule imparts energy to photons,dampening of the molecular vibrational amplitude results. In reversephotophoresis, also illustrated by FIG. 4A, the transfer of energy isfrom media particles to photons. The use of both photophoresis andreverse photophoresis allows for energy to be imparted to and capturedfrom media particles. Some embodiments of the present disclosure employreverse photophoresis.

By employing a large number of photons in the momentum exchange with asingle molecule and applying such a planned momentum exchange to manymolecules, sound properties and direction of propagation or attenuationcan be finely controlled. The photons employed for the transfer ofenergy with an apparatus of the present disclosure can be of anywavelength within the entire electromagnetic spectrum. Properties ofsound including frequency, loudness, timbre, and/or phase can be encodedas photon properties. An exemplary apparatus defines the properties ofphotons prior to the exchange of energy with media particles ordetermines the properties of photons after the exchange of energy withmedia particles. In the former case, the apparatus imparts the soundproperties encoded as photon properties to the media particles withwhich the photons interact. In the latter case, the apparatus detectsfrom photons the sound properties imparted by the media particles to thephotons with which the media particles interact.

Photons generated by an exemplary apparatus are transmitted to targetlocations in the media for sound recording, manipulation and generation.The target location information is stored in an isotropic or anisotropicmedium such as crystal 130.

In other exemplary embodiments, target location information is stored inconventional memory, such as, for example, electronic digital memory.The digital data is read from the memory and converted to optical form,aka photons, so that the information can be processed by the dynamicholographic processor. The reading of digital memory and thedigital-to-optical conversion processes will increase the latency of thesystem hence optical storage is preferred.

With reference to the exemplary apparatus of FIG. 1, the interaction ofphotons from lasers 120, 140 with crystal 130 results in linear ornon-linear scattering effects and linear or non-linear propagation, withphotons being distributed to the target locations. Examples of crystalsthat can be employed for non-linear effects include photonic crystals,meta-materials and photonic hypercrystals, such as described in“Photonic Hypercrystals” by Evgenii E. Narimanov. Crystals that producelinear scattering effects such as Diffractive Optical Elements can alsobe used. The crystal acts as a waveguide for the laser light. Severalconventional approaches for non-mechanical beam steering include the useof holographic optical elements, liquid crystals and photonic crystalsfor dynamic time-varying optical path changes. These conventionaltechniques can be used to dynamically change the path of photons usingcrystal 130. Photons from crystal 130 are transmitted along variouspaths to arrive at a target location simultaneously. The simultaneousarrival of photons will result in the combined impact of photons at thattarget location.

A highly directional and efficient method of free space optical wavecommunication is described in “A self-adaptive method for creating highefficiency communication channels through random scattering media,” byXiang Hao, Laure Martin-Rouault, & Meng Cui. The method explains how toreduce the scattering effect of random scattering media on photons andhow to achieve self-adaptive, non-linear photon path propagation. Suchpropagation can be advantageously employed for efficient communicationsin embodiments of this disclosure.

The benefits of the above described energy exchange between photons andmedia particles for sound recording, manipulation and creation are vastcompared to conventional techniques. By eliminating mechanicaldiaphragms, electronics and cables, the sound quality of the originalsource is preserved. The following illustrate the capabilities ofembodiments of the present disclosure.

Flat frequency response: The exchange of energy between photons andmedia particles introduces no distortion and is hence able to provide aflat frequency response. Unlike existing electronics-based systems, nomicrophone preamplifier related clipping or overloading is present.

Large dynamic range: Dynamic range is defined as the difference in SoundPressure Level (SPL) between noise floor and the maximum SPL. The noiseintroduced in the energy exchange between photons and media particles isnegligible. Since noise is nearly zero in this energy exchange, thedynamic range is a very large number, and many orders of magnitudegreater than can be perceived by a human ear. The maximum SPL that canbe achieved is many orders of magnitude higher than required forpractical use.

Frequency range: The frequency range of sound that can be recorded,stored, manipulated, distributed and generated with embodiments of thepresent disclosure covers the entire sound spectrum from nearly zero Hzto the end of the ultrasonic frequency range. This is a significantimprovement over any sound equipment including microphones,loudspeakers, mixers, and associated electronic components.

Directionality/Polar Pattern: Any polar pattern and directionality canbe achieved for sound recording and pressure wave creation in accordancewith the present disclosure. Because the precision of transmittingphotons to target locations is extremely high, nearly perfectomnidirectional recording can be achieved. Directionality is not soundfrequency dependent.

Channel Separation/Crosstalk: There is no crosstalk between soundchannels; i.e. channel separation is infinite. This can be achievedsince there is no common shared electrical signal. A set of discretephotons carries the sound data of a single channel.

Latency: Latency introduced by sound recording, distribution,manipulation and pressure wave creation depends on the speed of photonsin the medium and the physical properties of the medium. For most commonmedia such as air, water, animal tissue, plastic and glass, the speed ofphotons is relatively high and for most common applications thedistances of transmission are small, such that latency is imperceptibleby humans. This is a significant improvement in latency over digitalsystems. The latency experienced with embodiments of the presentdisclosure for recording, manipulating and creating sound pressure wavesin air at nearby locations (e.g., within meters) would be on the orderof picoseconds. Digital mixers, for example, exhibit an unavoidableamount of latency or propagation delay, ranging from 1.5 ms to as muchas 10 ms, which can be disorienting and unpleasant to a user.Embodiments of the present disclosure do not require encoding in formatssuch as MPEG AAC, as long as the sound data is kept in the opticaldomain. This minimizes the processing required and minimizes latency.

Number of sound channels, sampling and bandwidth: Many photons areemployed in the transfer of energy with a single particle or moleculeand the transferred information will be carried by more than one photon.A collection of photons directed to a single target location (particle)will be encoded with sound properties for that location. The task ofdetermining the sound properties of each collection of photons andsubsequently encoding with sound properties these photons falls underthe information processing function of the crystal. Since eachcollection of photons has properties independent of other collections,channel separation is maintained for sound generation. For soundrecording, a similar technique is used wherein collections of photonsare directed towards their target locations. After energy exchange withmedia particles, the returning collections of photons enter the crystaland the properties of the media particles are provided by the resultantnon-linear paths of the photons in the crystal. The collections ofphotons can be distinguished from each other by their properties. Thenumber of sound channels and bandwidth can thus be extremely large.Sampling is actually performed at the rate at which the media particlescan be displaced. Due to the large bandwidth and number of channels, asound pressure wave can be perfectly replicated and apparatus inaccordance with the present disclosure can record, manipulate,distribute and create sound pressure waves for a true 3-D sound image.

Distribution losses and noise: Exemplary embodiments of the presentdisclosure use photons to transfer sound from one location to another.Sound distribution via photons is an efficient transmission process.Common noise, radio frequency interference and mains hum have no impacton the sound. Exemplary embodiments eliminate the need for a soundreinforcement system that is complex and costly. The photons can betransferred using multiple optical repeaters to the desired sound wavecreation locations with minimal transmission losses.

Storage medium read and storage rate: Large data rates can beaccomplished for storing and retrieving information from optical storagemedia since the store and read rates are on the order of the speed oflight.

Flexibility: The location of a generated sound image can be variedwithout changing the location of the apparatus generating the soundimage. This is a significant improvement over current loudspeakers thatare fixed in position or ultrasonic transducers that must be moved overa patient's body. Significantly greater control in sound recording,manipulation and creation can be provided with a single apparatus,including the ability to vary the location of sound recording,manipulation and pressure wave creation without changing apparatuslocation, and the ability to provide continuous instead of discretevariation in the polar pattern. Exemplary embodiments also have theflexibility to work in more than one media, such as but not limited toair, water, plastic, human tissue and glass.

Power consumption: The power required to record sound, distributephotons and create sound pressure waves is provided by the power sourcethat is driving the lasers. The energy transfer process between mediaparticles and photons is highly efficient and can be finely controlled.The power required by exemplary apparatuses to perform the same functionis much lower than conventional recording, distribution and loudspeakerdevices.

Cost: The elimination of electronics for sound recording, manipulationand pressure wave creation and the elimination of distribution equipmentsuch as amplifiers and cables result in lower cost and complexity ofexemplary sound equipment. A single apparatus can provide significantflexibility to control the recording, distribution, manipulation andgeneration of sound.

Size and Packaging: Exemplary apparatuses can be made more compact thancurrently available electronic apparatuses of similar functionality. Nospecial packaging, such as with MEMS technology and loudspeakers, isrequired with exemplary apparatuses since all transduction occurs in themedium between photon and medium particles, and no special protection isrequired from radiated disturbances for sound distribution.

Other types of electronic and optical apparatuses, such as, but notlimited to, mobile phones, desktop computers, laptop computers, tabletcomputers, media players, televisions, gaming devices, cameras, videorecorders, positioning devices, electronic books, wearable devices,projector devices, vehicles, analog and digital sound equipment andother types of electronic and optical systems, may be implemented inaccordance with the present disclosure.

FIG. 5 shows a block diagram of an exemplary apparatus 500 comprising anoptical system 560 which can be implemented with apparatus 100 ofFIG. 1. Apparatus 500 may have its own set of controls 510 in additionto or instead of the controls 110 from FIG. 1. Apparatus 500 includes anelectronic transmitter 520 and receiver 530, which in exemplaryembodiments transmit and receive ultrasonic or electromagnetic waves(e.g., radio or terahertz frequency) that are used for determiningtarget locations for sound recording, manipulation and pressure wavecreation. Electromagnetic wave transmission, reception and processing isdistinguished from photon based transmission, receiving and processingin that electromagnetic wave receivers, transmitters and associatedprocessing require electronics, whereas photon based distribution,receiving and processing do not. As such, one or more components ofapparatus 500 can be implemented in electronic, opto-electronic orall-optical forms. Transmitter 520 and receiver 530, which are shown asseparate components, may be combined into a single component.

The return ultrasonic or electromagnetic waves received by receiver 530are processed by processor 550 to detect and determine the locations ofsurrounding objects and to perform pattern recognition so as to identifydetected objects. For example, the body and facial features of persons,especially substructures of the ears, such as the pinna, ear canal,ear-drum, cochlea or cilia, are located and tracked by the apparatus.These are known target locations for sound pressure wave creation. Suchfeatures can further be associated with and identified as belonging tospecific persons. Other structures of the body such as the mouth can belocated and tracked for sound pressure wave recording, while the pelvis,legs, arms, neck, abdomen and other structures can be assigned asreference locations which can be used to define target locations forsound creation, manipulation and creation. These target locations may beused for ultrasonic sound pressure wave creation as administered duringultrasound imaging and medical procedures. Other features of objectsincluding but not limited to shapes, edges, and surfaces can be used forobject classification.

Processor 550 estimates individualized Head Related Transfer Function(HRTF) from return data (such as ultrasonic or electromagnetic wavereturn), generates and refines HRTF estimations and target locationestimations by learning over multiple ultrasonic returns, and employs aclassifier to classify features of objects. The return from objects,including walls, is used to estimate reverberation effects and thelocations of the objects. Optical system 560 receives the targetlocation information from processor 550 over an optical, wired orwireless interface.

Processor 550 may perform any other processing besides that describedabove. The processor can include any analog, digital or hybridelectronic circuit and combination of circuits, the primary function ofwhich is to process the data received from receiver 530 and opticalsystem 560. The processor can include any integrated circuit such as aField Programmable Gate Array (FGPA), Application-Specific IntegratedCircuit (ASIC), a Central Processing Unit (CPU) or combination of suchprocessors.

Apparatus 500 includes a sound input component 540 that receives anelectrical input signal representing sound, such as over a physicalconnector or over the air using a wireless link such as Bluetooth orWifi. The signal is then sent to processor 550 for processing, includingbut not limited to channel separation, modeling of 3-D sound field,modeling of reverberation effects, HRTF and other transfer functioncorrections, correcting for reverberation effects, and adding soundeffects or changing the sound frequencies, loudness, timbre, or phaseand any combination thereof, based on the settings of controls 510. Theprocessed sound data is transmitted from processor 550 to optical system560 by photons over a wired or wireless interface.

Controls 510 are similar to controls 110 in FIG. 1. The controls can beused to define target locations (including zones which are a collectionof target locations) in which, or at the boundaries of which, soundpressure waves are recorded, manipulated and/or created. The controlscan also used to define the properties of sound pressure waves thattravel across the boundaries of and within a defined volume or zone.

Once the necessary processing of sound data is complete, optical system560 transmits photons to the target locations, where the energy transferbetween photons and media particles can take place from photons to mediaparticles, media particles to photons or both. The sound input from 540,or sound transmitted to the apparatus from another optical apparatus,such as depicted in FIG. 2, or sound stored internally in apparatus 560is distributed by the photons and then pressure waves are created at thetarget locations. For sound recording, the photons at the targetlocations are imparted with energy from media particles at the targetlocations.

The transmit and receive functions of 520 and 530 can also be performedby optical system 560, in another embodiment in which the transmittedwaves, such as ultrasonic waves, are generated using the lasers andisotropic or anisotoropic material, and the received waves are convertedback to photons. In this exemplary embodiment, optical system 560generates and receives ultrasound by transferring energy from photons tomedia particles (transmitter operation) and from media particles tophotons (receiver operation). The photons obtained from the receiveroperation are then optically processed by processor 550, which in thisembodiment is an optical processor (or computer) and is able to detectand classify surrounding objects.

In another embodiment, photons from optical system 560 are transmitteddirectly to the surroundings and optical system 560 receives the photonreturn. Processor 550 processes the received photons, and based on thereceived photon properties, surrounding objects are detected andclassified. If the apparatus is constructed as a true optical device(i.e., without electronics for transmission, receiving and processing),then the components 520 and 530 are not required as 550 and 560 performall the electronic functions in the optical domain.

Benefits of embodiments of the present disclosure will now be discussed.

Minimal Soundproofing and Noise Reduction: The ability to locate earsand create sound pressure waves at the ears means that reverberationeffects are reduced significantly for listeners. This minimizes the needfor noise barriers, sound baffles and anti-noise sound generators.Similarly, the ability to record sound at the mouth location reduces theamplitude of unwanted surrounding noise.

Ease of use: Locating and tracking ears eliminates the need to wearheadsets, earphones and other sound devices worn over ears. Similarly,since mouths can be located and tracked, the apparatus eliminates theneed to wear or hold microphones.

Listener and Speaker Location Flexibility: Real-time tracking of thelistener or speaker (animate or inanimate) allows the location of thespeaker or listener to change relative to the apparatus, and theapparatus need not be in the immediate vicinity of the speaker orlistener.

Real Time Sound Recording, Distribution and Power Efficiency: Theability to determine the real-time locations of listeners and speakers(animate or inanimate) can be used to determine locations for soundpressure wave creation, manipulation and recording. Locations betweenthe apparatus and speakers or listeners that do not require soundpressure wave creation or recording can be excluded as target pressurewave creation and recording locations. This provides power consumptionefficiency in sound creation, distribution, manipulation and recording.

FIG. 6 depicts an exemplary method for determining target locations,transmitting photons to the target locations, and recording,manipulating or creating sound pressure waves. A target location may beany location, including a location where a living object or part of itis present, including but not limited to humans, animals, and plants; ora location where a non-living object is present, including but notlimited to a repeater, router, recording or loudspeaker device. FIG. 6illustrates the use of electromagnetic waves, ultrasonic or photontransmission at 610, receipt of the return at 620, and processing of thereturn at 630 to detect sound recording, manipulation and pressure wavecreation target locations, such as the locations of a listener's mouthor ears, for example. At 640, photons are transmitted to the targetlocations. At 650, energy is exchanged between photons transmitted tothe target locations and media particles.

When the objects for which target locations are defined move or theapparatus moves, the apparatus continues to transmit and process returnsso that the relative or absolute locations of the living or non-livingobject are tracked in real time. Tracking of ears or lips (or mouth) ofa person is performed especially when a recording or creation volume hasbeen defined as described below.

In another embodiment, sound is distributed to one or more targetlocations by detecting an object and determining target sound pressurewave creation locations with reference to the object. The object beingdetected can be one or more, partial or whole, animate or inanimateobjects and the zone can be defined in relation to the detected objects.An example of this embodiment uses an object such as a human head or thewalls of an auditorium. In this example, faces or heads can be used fordetermining the approximate locations of ears and a target location forsound recording and pressure wave creation can be determined relative tothe location of the ears. Similarly, walls can be defined as the objectsuch that all target locations are within the confines of the walls. Thetarget locations for sound pressure wave recording, manipulation andcreation may be distributed in space relative to the objects. At thedistributed target locations, sound pressure wave creation would allowall objects to receive the sound pressure waves. The same approach isused to record sound from multiple sound generating objects by recordingsound at distributed target locations.

In another embodiment of this method, the target locations aredistributed in the media at numerous locations based on a 3-D model ofthe sound field such that the sound recorded is 3-D sound or the soundsynthesized at each target location gives the listener an immersive 3-Dexperience. Exemplary apparatus may define the volume size and shape ofthe 3-D sound field based on the locations of objects.

Although described in various embodiments and illustrated in FIG. 6,this method does not necessarily require the detection of listener andspeaker locations by the apparatus. Instead, a user may manually definethe target locations for sound pressure wave creation, modification orrecording by the apparatus provided controls.

FIG. 7 shows an illustrative recording zone that is defined around aperson's mouth. FIG. 8 shows sound creation zones that are definedaround the ears. Each of the zones can be defined as one or moresurfaces or a volume. If a zone boundary is defined by a surface orplurality of surfaces that do not enclose a volume then the defined zonecan extend indefinitely. In another scenario, the surface or pluralityof surfaces can form an enclosed volume by intersection with physicalobjects such as the walls of a building.

A recording zone, such as depicted in FIG. 7, is a zone where energy ofsound pressure waves is transferred to photons for recording. A soundcreation zone, such as depicted in FIG. 8, is a zone where energy ofphotons is transferred to media particles to create sound pressurewaves. The properties of sound at the boundaries of a recording orcreation zone can be controlled such that properties of sound wavescrossing the boundary into or out of the zone are varied as the soundwaves cross the boundary. Zones can be created for audible as well asinaudible sound (i.e., infra- or ultrasound).

A manipulation zone is a type of zone for the manipulation of soundproperties, and may or may not involve the creation or recording ofsound pressure waves. An example of a manipulation zone is a silencezone, in which sound creation or the transmission of sound therein isrestricted by photons absorbing all the energy of surrounding mediaparticles at the boundaries of the zone. An effective means of noiseinsulation is the creation of an insulating layer by pushing the mediaparticles away from each other on opposite sides of an imaginary planeor complex surface. This requires much less power than active noisecancelation since the power required for active noise cancelation isequal to the power of the oncoming sound pressure waves.

A manipulation zone can be defined such that it is applicable to onlycertain types of sounds, the properties of which meet defined criteria.The criteria can be defined so as to result in noise cancellation. Thesound properties may be defined for either specific portions of theboundary of the zone, the oncoming sound pressure waves, the outgoingsound pressure waves or a combination of these.

The controls (110, 510) of the apparatuses (100, 500) can be used todefine zones associated with an object by defining features of theobject, such as its shape or size. Detection may also be performed basedon a predefined object whose definition is stored in crystal 130, suchas a mouth object shown in FIG. 7 and ear objects shown in FIG. 8. Upondetection of an object such as a mouth or ear, zones are established bypropagating photons to locations relative to the object. Optical system100 uses the inputs of controls 110 to determine the physical region in3-D space (zones) where sound pressure wave energy is ether controlledalong the boundaries of the defined volume, within the volume or alongthe set of defined surfaces. Using non-collinear photon propagation, acomplex shaped zone can be created conforming to a predetermined shapeor the complex zone can be created as a dynamically varying shape. Thedetected objects may become references for defining the zone boundary,i.e. the zone boundaries can be different from the object boundaries.

A user may place the apparatus near the object to be detected toincrease the probability of accurately locating the object and definingthe zone.

The apparatus controls the sound properties across the boundaries andinside the zone for recording, manipulation and sound pressure wavecreation. The apparatus accomplishes this by modifying one or more soundproperties, including, but not limited to, amplitude, pressure,intensity, frequency, speed, direction, phase and timbre.

FIG. 9 illustrates an exemplary method for generating and using soundrecording, manipulation and creation zones. At 910, zone boundaries aredefined using the apparatus controls. At 920, the apparatus transmitsphotons to the boundary of the defined zone or to the entire volume ofthe zone. Depending on the type of zone as determined at 930, energy istransferred between the media particles and the photons, at 940, 950 or960. In the case of a recording zone, energy is transferred at 940 frommedia particles to photons. In the case of a manipulation zone, energymay be transferred at 950 from media particles to photons, from photonsto media particles or both. In the case of a creation zone, energy istransferred at 960 from photons to media particles. The energy transferthat takes place is such that the resulting sound from the energyexchange has the properties that were defined for the zone in 910.

Precise measurements of sound properties within a recording zone can beaccomplished by preventing noise surrounding the zone from entering thezone along the zone boundary. This makes exemplary apparatuses extremelyefficient in measuring sound pressure level or other sound properties,such as may be performed when operated as a phonometer.

Several benefits of exemplary apparatuses will now be discussed.

No physical materials for soundproofing are needed. Instead, photons aretransported to the zone boundaries or to locations within the volume ofthe zone. This provides an easy, low cost approach that is not possiblewith existing soundproofing or noise reduction measures. It can be usedin applications where space or weight constraints restrict the use ofphysical materials. Present devices for noise control require physicalmaterials in order to constrain or eliminate the sound.

A zone can be defined using a volume or surface of any 3-dimensionalcomplexity.

The apparatus provides the flexibility to modify the zone boundary andthe sound properties of the zone using the apparatus controls. This doesnot require movement of any physical materials such as soundproofingmaterials.

FIG. 10 shows a system 1000 for generating and processing ultrasonicpressure waves that includes an optical system 1020, such as opticalapparatus 100 of FIG. 1. Controls of system 1020 or additional controls1010 are used to define the location and size of the ultrasonic pressurewave creation and recording zones, which may otherwise be pre-encoded inthe crystal of optical system 1020. In addition to the modes and methodsof scanning, controls 1010 are used additionally to change properties ofthe ultrasonic wave, including but not limited to: intensity, beamangle, beam spread, center frequency, bandwidth, and pulse width.Optical system 1020 directs photons to the target locations, and causesthe photons to transfer energy to the surrounding media particles togenerate ultrasonic sound pressure waves. The energy of the reflected ortransmitted ultrasonic waves is transferred back to photons at thetarget sensing locations. The target sensing and pressure wave creationlocations may be the same or different locations. The ultrasonic scandata is processed using photon based optical processing and theprocessed data can be presented on a display as a hologram.

FIG. 10 also shows an optical receiving and digital display system 1030,which is an optional system that can interact with system 1000. Anoptical receiver 1040 of system 1030 receives photons carryingultrasonic and other unprocessed or processed data from system 1000 andconverts the optical data to a digital signal using an optical todigital signal converter 1050. The digital signal is sent to the digitalprocessor 1060 that processes the raw data and may further processpre-processed data from system 1000. The processed data is sent to anelectronic display 1070 where the processed ultrasonic scan data isdisplayed.

For therapeutic applications such as ultrasonic heating, system 1000 maybe used alone. The combination of systems 1000 and 1030 may be used fordisplaying images while other processes such as ultrasonic based heatingare performed by system 1000. For applications such as but not limitedto elastography, where multiple ultrasonic pressure waves havingdifferent properties are transmitted and received, system 1000 issufficient to produce all the required ultrasonic pressure waves.However, system 1000 can also transmit photons to one or more otheroptical systems like system 1000, which would also generate ultrasoundpressure waves at the same or different target locations. This issimilar to the concept shown in FIG. 2.

Optical system 1000 records the ultrasonic data received via energyexchange between photons and reflected ultrasonic waves by storing thisdata in its crystal. The data stored optically can be processed anddisplayed at the time of recording the data or any time during or afterwhich ultrasonic pressure waves are created and received.

For endovaginal, endorectal, transesophageal and other applicationswithin the body, an exemplary embodiment of optical system 1000 can bemounted on a small diameter catheter or other means and placed into thebody such as through blood vessels to image the walls and disease ofthose vessels. Optical system 1000 can communicate via photontransmission with system 1030, which resides outside the patient's body.

The benefits of this embodiment for medical and industrial applicationsare similar to those described earlier for system 100. A singleapparatus 1000 can be used as both the transmitter and receiver and asone or more transceivers. A coupling medium is not required and theapparatus does not need to be in contact with the material or bodyreceiving the ultrasonic pressure waves, hence the use of the ultrasonicapparatus is less reliant on operator skill and does not pose a risk ofinfection or contamination. The apparatus provides a flat response overa wide frequency range, and compared to other types of transducers canprovide a larger frequency range, larger dynamic range, larger maximumpressure output, better receive sensitivity while providing a highcoupling efficiency, and higher signal to noise ratio. The number ofchannels can be much higher than the 96 to 512 channels used today, thusproviding higher imaging quality.

FIG. 11 shows an exemplary apparatus 1100, which includes two lasers1110 and 1120, and laser driving and switching circuitry 1130. Lasers1110 and 1120 are positioned to direct the laser beams towards eachother and so that the axes of both beams are collinear. The co-linearityof the beams is essential for maximum efficiency of the photophoreticaction. The lasers are separated by a medium such as air and can besubstituted with any medium within which photophoretic action is desiredto produce sound. The laser driving and switching circuitry 1130operates the lasers so as to alternately activate the laser so thatlaser 1110 is on while 1120 is off and vice-versa.

The switching on and off of each laser is performed at frequency fresulting in sound generated at frequency f. The on and off switching ofthe lasers generates an oscillating momentum transfer from the photonsto the medium particles. The resulting vibrations produced in the mediumgenerate a sound pressure wave.

Apparatus 1100 can be combined with controls to modify the soundproperties such as frequency and loudness. Apparatus 1100 essentially isa speaker. The driver and switching circuitry 1130 can also becontrolled by a processor. The processor converts sound data intoproperties such as sound frequency, intensity, and sound generationlocation that is transferred to driver and switching circuitry 1130 tocontrol the lasers 1110 and 1120 to generate sound. The speaker can beused in various sound applications such as music and ultrasonicapplications.

In an exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls; encode the selectioninputs as photon properties; transmit the photons to target locations,wherein one or more properties of the photons are affected by thetransfer of energy from sound pressure waves to the photons; and detectthe one or more properties of the photons thus affected. With referenceto FIGS. 12A-12C, an exemplary implementation includes elements 10, 20,30, 40 a, 50, 60, 90, 100, 110 290, 320, 330, 290 and 370. Elements 40 band 40 c may also be included. Additionally, object detection,recognition, identification and tracking (shown as Path A) can beincluded to track a user's mouth and to generate a recording zone in amicrophone application. Implementations of such an apparatus can be usedto replace, for example, conventional microphones, or ultrasonicreceivers.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls; read sound data encodedas photon properties from photons transmitted to the apparatus; modifythe photon properties to modify the sound data based on the selectioninputs; determine, via selection input, sound pressure wave creationtarget locations for transmission of sound information; transfer thesound information via photons to the target locations; and create soundpressure waves at the target locations by transferring photon energy tomedia particles at the target locations. With reference to FIGS.12A-12C, an exemplary implementation includes elements 10, 20, 30, 40 a,50, 60, 70, 80 c, 90, 100, 110, 290, 340, 290, 310, 290, and 370.Elements 40 b and 40 c may also be included. Elements 80 a and 80 b mayalso be included. Additionally, object detection, recognition,identification and tracking (shown as Path A) can be included to track auser's ears and to generate a sound creation zone in a speakerapplication. Implementations of such an apparatus can be used toreplace, for example, conventional speakers, headphones or other suchsound generating devices including conventional playback devices such asaudio players, jukeboxes, or ultrasonic systems including transducers.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls; determine targetlocations from selection inputs or optically encoded data; transmitphotons to target locations; detect incoming sound pressure waves;transfer energy from the incoming sound pressure waves to photons;modify the photon properties based on the selection inputs optionally inorder to modify the sound data; and store the sound information encodedin the photons in the isotropic or anisotropic medium. With reference toFIGS. 12A-12C, an exemplary implementation includes elements 10, 20, 30,40 a, 50, 60, 90, 100, 110, 290, 320, 320, 290, 340, 290, 360, 290, and370. Elements 40 b and 40 c may also be included. Additionally, objectdetection, recognition, identification and tracking (shown as Path A)can be included to track a user's mouth and to generate a recording zonein a recording application. Implementations of such an apparatus can beused to replace, for example, conventional sound recorders with storagemedium, or ultrasonic systems comprising ultrasonic receivers and datastorage.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls; optically read sound dataencoded as photon properties that are transmitted to the apparatus fromanother apparatus; optionally modify the sound data in accordance withthe selection input; and store the sound information encoded in thephotons in the isotropic or anisotropic medium. With reference to FIGS.12A-12C, an exemplary implementation includes elements 10, 20, 30, 40 a,50, 60, 70, 80 c, 90, 100, 110, 290, 340, 290, 360, 290, and 370.Elements 40 b and 40 c may also be included. Elements 80 b may also beincluded. Implementations of such an apparatus can be used to replace,for example, conventional sound recorders that receive audio data via awired or wireless connection.

In yet another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls; read optically encodedsound data in photons that are transmitted to the apparatus from anotherapparatus; modify the sound data in accordance with the selection input;identify target locations or apparatuses for transmission of soundinformation via the selection inputs; transfer photons to the targetsound pressure wave creation locations or apparatuses; and transferphoton energy to media particles at the target locations. With referenceto FIGS. 12A-12C, an exemplary implementation includes elements 10, 20,30, 40 a, 50, 60, 70, 80 c, 90, 100, 110, 290, 340, 290, 310, 290, 370.Elements 40 b and 40 c may also be included. Elements 80 a and 80 b mayalso be included. Implementations of such an apparatus can be used toreplace, for example, conventional synthesizers, karaoke devices, audiorepeaters, or mixing and mastering devices.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls, transfer photons to thetarget sound pressure wave recording locations, detect incoming soundpressure waves, transfer energy from incoming sound pressure waves intophoton energy, transfer the energy in the photons into visualdisplayable information, and store the optically encoded sound data inthe isotropic or anisotropic medium. With reference to FIGS. 12A-12C, anexemplary implementation includes elements 10, 20, 30, 40 a, 50, 60, 90,100, 110, 290, 320, 330, 290, 300, 290, 360, 290, and 370. Elements 40 band 40 c may also be included. Additionally, object detection,recognition, identification and tracking (shown as Path A) can beincluded to locate objects of interest and to generate a recording zone.Implementations of such an apparatus can be used to replace, forexample, conventional phonometers.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls, modify the soundinformation carried by photons originating in the device based on theselection input(s), identify target locations or apparatuses fortransmission of sound information, transfer the sound information viaphotons to the target sound pressure wave creation locations orapparatuses, and generate sound at the target sound pressure wavecreation locations by transferring photon energy to energy of mediaparticles. With reference to FIGS. 12A-12C, an exemplary implementationincludes elements 10, 20, 30, 40 a, 50, 60, 90, 100, 110 290, 350, 290,310, 290, and 370. Element 40 c may also be included. Additionally,object detection, recognition, identification and tracking (shown asPath A) can be included to track a user's ears and to generate a soundcreation zone. Implementations of such an apparatus can be used toreplace, for example, conventional musical instruments with speaker oraudio transmission systems.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls that are associated withone or more sound sources, read optically encoded sound data from theisotropic or anisotropic medium, read optically encoded sound data inphotons that are transmitted to the apparatus from one or more otherapparatuses, use the selection input to modify the photon properties inorder to modify the sound data for each sound source, store the combinedsound data in the isotropic or anisotropic medium, identify targetapparatuses for transmission of sound information, and transfer thesound information via photons to the apparatuses. With reference toFIGS. 12A-12C, an exemplary implementation includes elements 10, 20, 30,40 a, 50, 60, 70, 80 a, 80 c, 90, 100, 110 290, 340, 290, 360, 290, 350,290, and 370. Elements 40 b and 40 c may also be included. Element 80 bmay also be included. Implementations of such an apparatus can be usedto replace, for example, conventional mixers or digital soundworkstations.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: detect oneor more selection inputs provided by controls, transmit photons totarget locations determined from the selection inputs, detect photonsreturned from target locations and surroundings and identify photonproperties, process the returned photon data using optical computing,from the processed data detect objects, and classify the detectedobjects into known objects such as human body parts (ears, nose, orhead), man-made and natural objects (windows, walls, or trees). Theapparatus may be further adapted to determine target sound pressure wavecreation locations, and/or perform object identification based on thedetected objects. With reference to FIGS. 12A-12C, an exemplaryimplementation includes elements 10, 20, 30, 40 a, 50, 60, 90, 120, 130,140, 150, 160, 170, 180, 190,100, 115, 290, and 370. Elements 40 b and40 c may also be included.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources, atleast one isotropic or anisotropic medium and integrated with anelectronics based ultrasonic transmitter, receiver and electronicprocessor, is adapted to: detect one or more selection inputs providedby controls, transmit ultrasonic waves from the ultrasonic transmitter,process the ultrasonic return using the electronic processor, detect,classify and identify surrounding objects using the processor, anddetermine the target locations based on the input(s). With reference toFIGS. 12A-12C, an exemplary implementation includes elements 10, 20, 30,40 a, 50, 60, 90, 120, 200, 210, 220, 150, 160, 170, 180, 190, 100, 110,290, 370. Elements 40 b and 40 c may also be included.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources, atleast one isotropic or anisotropic medium and integrated with anelectronics based radiofrequency transmitter, receiver and electronicprocessor, is adapted to: detect one or more selection inputs providedby controls, transmit radiofrequency waves from the radiofrequencytransmitter, process the radiofrequency return using the electronicprocessor, detect, classify and identify surrounding objects using theprocessor, and determine the target locations based on the input(s).With reference to FIGS. 12A-12C, an exemplary implementation includeselements 10, 20, 30, 40 a, 50, 60, 90, 120, 200, 210, 220, 150, 160,170, 180, 190, 100, 110, 290, and 370. Elements 40 b and 40 c may alsobe included.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining one or more zones, said information being providedby one or more selection inputs of controls; transmit photons to thetarget locations defining zone boundaries or volume; determine soundproperties of the zone from the selection inputs; and transfer energy ofmedia particles to photons for only the sound pressure waves thatoriginate within the zone. With reference to FIGS. 12A-12C, an exemplaryimplementation includes elements 10, 20, 30, 40 a, 50, 60, 90, 100, 110,290, 320, 330, 290, and 370. Elements 40 b and 40 c may also beincluded. Additionally, object detection, recognition, identificationand tracking (shown as Path A) can be included to track a user's mouthor detect room walls and to generate a recording zone. Implementationsof such an apparatus can be used to replace, for example, conventionalwindscreens or sound recording rooms.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining one or more zones and sound properties of the zone,said information being provided by one or more selection inputs ofcontrols; transmit photons to the zone boundaries or volume; and use thesound properties to modify sound pressure waves traveling through thedefined zone by the exchange of energy between media particles andphotons. With reference to FIGS. 12A-12C, an exemplary implementationincludes elements 10, 20, 30, 40 a, 50, 60, 90, 100, 110, 290, 340, 290,310, 290, and 370. Elements 40 b and 40 c may also be included.Additionally, object detection, recognition, identification and tracking(shown as Path A) can be included to detect or track objects that definea sound manipulation zone. In an exemplary implementation, the exchangeof energy takes place at the boundaries of a zone so that the resultingsound in the zone is in accordance with the selected properties, suchas, for example, a silence zone where no sound reaches. A zone volumemay also be defined so that a gradient of sound properties may beformed, such as, for example, a gradual increase in sound pressure levelwithin the volume so that energy exchange is not limited to theboundaries of the zone but also occurs across the zone volume.Implementations of such an apparatus can be used to replace, forexample, conventional soundproofing materials, or noise reductiondevices.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining one or more zones, said information being providedby one or more selection inputs of controls; modify the properties ofphotons generated by the device based on the information; transferphotons to the zone boundaries or volume; and generate sound pressurewaves only in the zone by transferring energy from photons to mediaparticles. With reference to FIGS. 12A-12C, an exemplary implementationincludes elements 10, 20, 30, 40 a, 50, 60, 70, 80 a, 90, 100, 110, 290,340, 290, 310, 290, and 370. Elements 40 b and 40 c may also beincluded. Elements 80 a and 80 b may also be included. Additionally,object detection, recognition, identification and tracking (shown asPath A) can be included to detect or track objects that define a soundcreation zone. Implementations of such an apparatus can be used toreplace, for example, conventional speaker arrays that produce audiozones.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining one or more types of objects and target locations,said information being provided by one or more selection inputs ofcontrols; transmit photons to the target locations; process the photonproperties after their interaction with the object (such as by usingoptical computing) to determine if the defined object types are found,determine target locations from detected objects, and encode locationproperties as photon properties. With reference to FIGS. 12A-12C, anexemplary implementation includes elements 10, 20, 30, 40 a, 50, 60, 90,120, 130, 140, 150, 160, 170, 180, 190, 100, 115, 290, and 370. Elements40 b and 40 c may also be included. Implementations of such an apparatuscan be used to replace, for example, conventional video cameras andsystems performing object recognition and identification.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining one or more zones, sound properties and targetlocations, said information being provided by one or more selectioninputs of controls; modify the properties of device generated photonsbased on the information; transfer photons to the target locations,generate sound pressure waves at target locations by transferring photonenergy to media particles when a defined object or object type (livingor non-living) is detected in a certain location with respect to thedefined zone such as when the object crosses the defined zone boundary;and storing the object type properties and time data in the isotropic oranisotropic medium. With reference to FIGS. 12A-12C, an exemplaryimplementation includes elements 10, 20, 30, 40 a, 50, 60, 70, 80 a, 90,A (any branch), B, 100, 115, 100, 110, 290, 310, 290, and 370. Elements40 b and 40 c may also be included. Elements 80 a and 80 b may also beincluded. Continuous object tracking is implemented by repeating thesequence: path A, path B, element 100, and element 115. Implementationsof such an apparatus can be used to replace, for example, conventionalmotion detectors.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining one or more zones and noise rejection properties ofthe zones, said information being provided by one or more selectioninputs of controls; transfer photons to the zones, determine andcharacterize the noise within, surrounding, or at the boundaries of thezones by transferring some or all of the media particle energy tophotons; and generate sound pressure waves within, surrounding or at theboundary of the defined volumes by transferring energy from mediaparticles to photons, resulting in cancellation of the noise within,surrounding, or at the boundaries of the zones in accordance with thedefined noise rejection properties. With reference to FIGS. 12A-12C, anexemplary implementation includes elements 10, 20, 30, 40 a, 50, 60, 90,100, 110, 290, 320, 330, 290, 340, 290, 310, 290, and 370. Elements 40 band 40 c may also be included. Additionally, object detection,recognition, identification and tracking (shown as Path A) can beincluded to detect or track a user's ears that define a noisecancellation zone. Implementations of such an apparatus can be used toreplace, for example, conventional active noise-cancelation devices.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining one or more zones and noise rejection properties ofthe zones, said information being provided by one or more selectioninputs of controls; transfer photons to the zones, transfer energy fromphotons to media particles to modify the distance of media particlesfrom each other resulting in modified sound in accordance with thedefined noise rejection properties. With reference to FIGS. 12A-12C, anexemplary implementation includes elements 10, 20, 30, 40 a, 50, 60, 90,100, 110, 290, 320, 330, 290, 340, 290, 310, 290, and 370. Elements 40 band 40 c may also be included. Additionally, object detection,recognition, identification and tracking (shown as Path A) can beincluded to detect or track an object such as user's ears or room wallsthat define a noise cancellation zone. Implementations of such anapparatus can be used to replace, for example, conventional noisereduction materials and devices.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining ultrasonic pressure wave properties and targetpressure wave generation locations, said information being provided byone or more selection inputs of controls; and generate an ultrasonicpressure wave by transferring photonic energy to media particles at thetarget locations. With reference to FIGS. 12A-12C, an exemplaryimplementation includes elements 10, 20, 30, 40 a, 50, 60, 90, 100, 110,290, 310, 290, and 370. Elements 40 b and 40 c may also be included.Elements 80 a, 80 b and 80 c may also be included to receive ultrasonicwave data properties. Additionally, object detection, recognition,identification and tracking (shown as Path A) can be included to detector track objects that define a target ultrasound generation zone.Implementations of such an apparatus can be used to replace, forexample, conventional ultrasonic devices for heating, welding,soldering, and humidification.

In another exemplary implementation in accordance with the presentdisclosure, an apparatus comprising orthogonal laser light sources andat least one isotropic or anisotropic medium is adapted to: obtaininformation defining ultrasonic pressure wave properties and targetpressure wave generation locations, said information being provided byone or more selection inputs of controls; and generate an ultrasonicpressure wave by transferring photonic energy to media particles at thetarget locations. The energy of ultrasonic pressure waves reflected byor transmitted through one or more objects at the target locations istransferred from media particles to photons. The apparatus is furtheradapted to determine one or more properties of one or more objects byprocessing the photons that exchanged energy with the reflected and/ortransmitted ultrasonic pressure waves, such as by using photon basedprocessing, store this information in the isotropic or anisotropicmedium, and transmit this information to a display system, such as viaphotons. With reference to FIGS. 12A-12C, an exemplary implementationincludes elements 10, 20, 30, 40 a, 50, 60, 90, 120, 200, 230, 240, 250,260, 150, 160, 170, 180, 190, 100, 110, 290, 360, 290, 300, 290, and370. Elements 40 b and 40 c may also be included. Elements 80 a, 80 band 80 c may also be included to receive ultrasonic wave dataproperties. Elements 210 and 220 may also be included in place of 230,240, 250 and 260. Additionally, object detection, recognition,identification and tracking (shown as Path A) can be included to detector track objects that define a target ultrasound generation zone.Implementations of such an apparatus can be used to replace, forexample, conventional ultrasonic devices for imaging, metal flawdetection, parking assist, and liquid level measurement. Elements 150,160 and 170 pertain to classification of ultrasonic return, for e.g.,determination of high vs. low echogenicity, anisotropy, blood flow speedand direction and determining a tumor vs. tissue.

TABLE OF ACRONYMS 2-D, 3-D, 4-D 2-dimensional, 3-dimensional,4-dimensional MEMS Micro Electro Mechanical Systems FLAC Free LosslessAudio Codec ALAC Apple Lossless Audio Codec HDMI High DefinitionMultimedia Interface LCRS Left, Center, Right and Surround MIDI MusicalInstrument Digital Interface OSC Open Sound Control CPU CentralProcessing Unit dB Decibel ANC Active Noise Control RMS Root Mean SquareCMUT Capacitive Micro machined Ultrasonic Transducers SNR Signal toNoise Ratio UBM Ultrasonic BioMicroscope ARFI Acoustic Radiation ForceImpulse HMI Harmonic Motion Imaging SSI Supersonic Shear Imaging SMURFSpatially Modulated Ultrasound Radiation Force EMAT ElectroMagneticAcoustic Transducers SPL Sound Pressure Level HRTF Head Related TransferFunction

As per this disclosure, the example aspects above can be combined in anymanner to enhance functionality of the apparatus. The invention is notlimited to these example aspects. The invention is applicable to any ofa variety of sound generating, modifying, distributing and receivingmethods and apparatuses.

While this disclosure has been presented using some specific examples,those skilled in the art will recognize that the teachings of thisdisclosure are not thus limited. Accordingly, this disclosure should beonly limited by the scope of the claims attached hereto.

1. An apparatus comprising: a medium, the medium being isotropic oranisotropic and having photorefractive properties; a first coherentsource of photons; and a second coherent source of photons, wherein thefirst and second coherent sources of photons are arranged so that photonbeams emitted therefrom are directed onto the medium and are mutuallyorthogonal.
 2. The apparatus of claim 1 comprising an input signalsource, the input signal source including at least one of a selectioninput of a control, the medium, a storage medium and a remote apparatus.3. The apparatus of claim 2, wherein the input signal indicates a targetlocation to which photons are to be transmitted from the medium, thephotons being directed to the target location non-mechanically.
 4. Theapparatus of claim 2, wherein the input signal indicates one or moreproperties of sound pressure waves to be generated, modified, orrecorded by the apparatus outside the medium.
 5. The apparatus of claim2, wherein the input signal indicates one or more properties of objectsto be detected by the apparatus.
 6. The apparatus of claim 1, whereinthe medium includes a crystal.
 7. The apparatus of claim 1 comprising aprocessor.
 8. The apparatus of claim 7, wherein the processor is anoptical processor.
 9. A method comprising: determining a targetlocation; transmitting from a medium photons to the target location,whereby energy is transferred between the photons and media particles atthe target location thereby affecting at least one property of thephotons, wherein the medium is isotropic or anisotropic and the targetlocation is external to the medium; and detecting the at least oneproperty of the photons.
 10. The method of claim 9, wherein the energyis characterized by a sound pressure wave, including at least one of aninfrasound, audible sound and ultrasound sound pressure wave.
 11. Themethod of claim 10 comprising at least one of reproducing and recordingthe sound pressure wave in accordance with the detected at least oneproperty of the photons.
 12. The method of claim 9, comprising detectingone or more objects, wherein the target location is determined inaccordance with the one or more objects detected.
 13. A methodcomprising: affecting at least one photon property in accordance with aninput signal; determining a target location; transmitting from a mediumphotons with the at least one property to the target location, wherebyenergy is transferred between the photons and media particles at thetarget location thereby affecting one or more properties of the mediaparticles in accordance with the input signal, wherein the medium isisotropic or anisotropic and the target location is external to themedium.
 14. The method of claim 13, wherein the energy is characterizedby a sound pressure wave, including at least one of an infrasound,audible sound and ultrasound sound pressure wave.
 15. The method ofclaim 14 comprising generating the sound pressure wave at the targetlocation in accordance with the input signal.
 16. The method of claim15, wherein generating the sound pressure wave at the target locationincludes at least one of setting a loudness, frequency spectrum, pitch,echo, delay, reverberation, phase, distortion, noise level, filteringprofiles and Doppler amount of the sound pressure wave.
 17. The methodof claim 13 comprising modifying a pre-existing sound pressure wave atthe target location in accordance with the input signal.
 18. The methodof claim 17, wherein modifying the sound pressure wave at the targetlocation includes at least one of altering a loudness, frequencyspectrum, pitch, echo, delay, reverberation, phase, distortion, noiselevel, filtering profiles and Doppler amount of the sound pressure wave.19. The method of claim 13 comprising receiving the input signal from atleast one of a selection input of a control, a storage medium, and aremote apparatus.
 20. The method of claim 13 comprising detecting one ormore objects, wherein the target location is determined in accordancewith the one or more objects detected.
 21. An apparatus comprising: afirst coherent source of photons; a second coherent source of photons;and a controller for controlling the first and second coherent sourcesof photons; wherein photon beams emitted from the first and secondcoherent sources of photons are directed toward each other, arecollinear, and alternatingly impact a target location, such that theintensity of a sound produced at a target location is maximized.
 22. Theapparatus of claim 21, wherein a medium in which a sound pressure waveis generated is located at the target location.
 23. The apparatus ofclaim 22, wherein the controller includes at least one of a controlsignal input and a processor for controlling one or more properties ofthe sound pressure wave.
 24. The apparatus of claim 21, wherein thecontroller controls the first and second coherent sources of photons soas to alternatingly emit photons.